1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_CLIENT_CAMERA2_CAMERAMETADATA_CPP
18 #define ANDROID_CLIENT_CAMERA2_CAMERAMETADATA_CPP
19 
20 #include "system/camera_metadata.h"
21 #include <utils/String8.h>
22 #include <utils/Vector.h>
23 #include <binder/Parcelable.h>
24 
25 namespace android {
26 
27 /**
28  * A convenience wrapper around the C-based camera_metadata_t library.
29  */
30 class CameraMetadata: public Parcelable {
31   public:
32     /** Creates an empty object; best used when expecting to acquire contents
33      * from elsewhere */
34     CameraMetadata();
35     /** Creates an object with space for entryCapacity entries, with
36      * dataCapacity extra storage */
37     CameraMetadata(size_t entryCapacity, size_t dataCapacity = 10);
38 
39     ~CameraMetadata();
40 
41     /** Takes ownership of passed-in buffer */
42     CameraMetadata(camera_metadata_t *buffer);
43     /** Clones the metadata */
44     CameraMetadata(const CameraMetadata &other);
45 
46     /**
47      * Assignment clones metadata buffer.
48      */
49     CameraMetadata &operator=(const CameraMetadata &other);
50     CameraMetadata &operator=(const camera_metadata_t *buffer);
51 
52     /**
53      * Get reference to the underlying metadata buffer. Ownership remains with
54      * the CameraMetadata object, but non-const CameraMetadata methods will not
55      * work until unlock() is called. Note that the lock has nothing to do with
56      * thread-safety, it simply prevents the camera_metadata_t pointer returned
57      * here from being accidentally invalidated by CameraMetadata operations.
58      */
59     const camera_metadata_t* getAndLock() const;
60 
61     /**
62      * Unlock the CameraMetadata for use again. After this unlock, the pointer
63      * given from getAndLock() may no longer be used. The pointer passed out
64      * from getAndLock must be provided to guarantee that the right object is
65      * being unlocked.
66      */
67     status_t unlock(const camera_metadata_t *buffer) const;
68 
69     /**
70      * Release a raw metadata buffer to the caller. After this call,
71      * CameraMetadata no longer references the buffer, and the caller takes
72      * responsibility for freeing the raw metadata buffer (using
73      * free_camera_metadata()), or for handing it to another CameraMetadata
74      * instance.
75      */
76     camera_metadata_t* release();
77 
78     /**
79      * Clear the metadata buffer and free all storage used by it
80      */
81     void clear();
82 
83     /**
84      * Acquire a raw metadata buffer from the caller. After this call,
85      * the caller no longer owns the raw buffer, and must not free or manipulate it.
86      * If CameraMetadata already contains metadata, it is freed.
87      */
88     void acquire(camera_metadata_t* buffer);
89 
90     /**
91      * Acquires raw buffer from other CameraMetadata object. After the call, the argument
92      * object no longer has any metadata.
93      */
94     void acquire(CameraMetadata &other);
95 
96     /**
97      * Append metadata from another CameraMetadata object.
98      */
99     status_t append(const CameraMetadata &other);
100 
101     /**
102      * Append metadata from a raw camera_metadata buffer
103      */
104     status_t append(const camera_metadata* other);
105 
106     /**
107      * Number of metadata entries.
108      */
109     size_t entryCount() const;
110 
111     /**
112      * Is the buffer empty (no entires)
113      */
114     bool isEmpty() const;
115 
116     /**
117      * Sort metadata buffer for faster find
118      */
119     status_t sort();
120 
121     /**
122      * Update metadata entry. Will create entry if it doesn't exist already, and
123      * will reallocate the buffer if insufficient space exists. Overloaded for
124      * the various types of valid data.
125      */
126     status_t update(uint32_t tag,
127             const uint8_t *data, size_t data_count);
128     status_t update(uint32_t tag,
129             const int32_t *data, size_t data_count);
130     status_t update(uint32_t tag,
131             const float *data, size_t data_count);
132     status_t update(uint32_t tag,
133             const int64_t *data, size_t data_count);
134     status_t update(uint32_t tag,
135             const double *data, size_t data_count);
136     status_t update(uint32_t tag,
137             const camera_metadata_rational_t *data, size_t data_count);
138     status_t update(uint32_t tag,
139             const String8 &string);
140 
141     template<typename T>
update(uint32_t tag,Vector<T> data)142     status_t update(uint32_t tag, Vector<T> data) {
143         return update(tag, data.array(), data.size());
144     }
145 
146     /**
147      * Check if a metadata entry exists for a given tag id
148      *
149      */
150     bool exists(uint32_t tag) const;
151 
152     /**
153      * Get metadata entry by tag id
154      */
155     camera_metadata_entry find(uint32_t tag);
156 
157     /**
158      * Get metadata entry by tag id, with no editing
159      */
160     camera_metadata_ro_entry find(uint32_t tag) const;
161 
162     /**
163      * Delete metadata entry by tag
164      */
165     status_t erase(uint32_t tag);
166 
167     /**
168      * Swap the underlying camera metadata between this and the other
169      * metadata object.
170      */
171     void swap(CameraMetadata &other);
172 
173     /**
174      * Dump contents into FD for debugging. The verbosity levels are
175      * 0: Tag entry information only, no data values
176      * 1: Level 0 plus at most 16 data values per entry
177      * 2: All information
178      *
179      * The indentation parameter sets the number of spaces to add to the start
180      * each line of output.
181      */
182     void dump(int fd, int verbosity = 1, int indentation = 0) const;
183 
184     /**
185      * Serialization over Binder
186      */
187 
188     // Metadata object is unchanged when reading from parcel fails.
189     virtual status_t readFromParcel(const Parcel *parcel) override;
190     virtual status_t writeToParcel(Parcel *parcel) const override;
191 
192     /**
193       * Caller becomes the owner of the new metadata
194       * 'const Parcel' doesnt prevent us from calling the read functions.
195       *  which is interesting since it changes the internal state
196       *
197       * NULL can be returned when no metadata was sent, OR if there was an issue
198       * unpacking the serialized data (i.e. bad parcel or invalid structure).
199       */
200     static status_t readFromParcel(const Parcel &parcel,
201                                    camera_metadata_t** out);
202     /**
203       * Caller retains ownership of metadata
204       * - Write 2 (int32 + blob) args in the current position
205       */
206     static status_t writeToParcel(Parcel &parcel,
207                                   const camera_metadata_t* metadata);
208 
209   private:
210     camera_metadata_t *mBuffer;
211     mutable bool       mLocked;
212 
213     /**
214      * Check if tag has a given type
215      */
216     status_t checkType(uint32_t tag, uint8_t expectedType);
217 
218     /**
219      * Base update entry method
220      */
221     status_t updateImpl(uint32_t tag, const void *data, size_t data_count);
222 
223     /**
224      * Resize metadata buffer if needed by reallocating it and copying it over.
225      */
226     status_t resizeIfNeeded(size_t extraEntries, size_t extraData);
227 
228 };
229 
230 namespace hardware {
231 namespace camera2 {
232 namespace impl {
233 using ::android::CameraMetadata;
234 typedef CameraMetadata CameraMetadataNative;
235 }
236 }
237 }
238 
239 } // namespace android
240 
241 #endif
242